KR101476865B1 - Exposure device, exposure method, and device manufacturing method - Google Patents

Abstract

An x linear encoder constituted by a pickup 54x disposed on a measurement mount 51 opposed to an x-scale 58x fixed to a lower surface of a barrel 40 for receiving a projection optical system, The displacement of the lens barrel 40 is measured. In the configuration of the linear encoder, the path of the light through the light path between the pick-up 54x and the scale 58x is significantly shorter than that in the case of using an interferometer.

Description

TECHNICAL FIELD [0001] The present invention relates to an exposure apparatus, an exposing method, and a device manufacturing method,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus, an exposure method, and a device manufacturing method, and more particularly to an exposure apparatus and an exposure method for forming a pattern on an object by an energy beam and a device manufacturing method using the exposure apparatus or the exposure method ≪ / RTI >

BACKGROUND ART In a lithography process for manufacturing electronic devices such as semiconductor devices (integrated circuits and the like) and liquid crystal display devices, a step-and-repeat type projection exposure apparatus (so-called stepper) or a step-and-scan type projection exposure apparatus ) Are mainly used.

In this type of exposure apparatus, a position of a wafer stage for holding a substrate (hereinafter generically referred to as a wafer) such as a wafer or a glass plate is measured using a laser interferometer with reference to the lens barrel side of the projection optical system, And the position of the stage with respect to the projection optical system is controlled by using the measurement result (see, for example, Patent Document 1). Thereby, even if the position of the projection optical system is slightly changed by vibration or the like, the wafer stage can be accurately followed.

However, when the laser interferometer is used to measure the position of the wafer stage with respect to the lens barrel side of the projection optical system, the optical path length of the length measurement beam becomes about several hundreds of millimeters or more. For this reason, an error may occur in the measurement value due to temperature fluctuation (air fluctuation) of the atmosphere around the optical path of the measurement beam. This error may be caused by misalignment of the pattern formed on the wafer, Which is the cause of the overlapping error between the patterns of FIG.

Patent Document 1: United States Patent Application Publication 2007/0288121

(Disclosure of the Invention)

(MEANS FOR SOLVING THE PROBLEMS)

According to a first aspect of the present invention, there is provided an exposure apparatus for exposing an object through an optical member with an energy beam and forming a pattern on the object, comprising: a moving body holding the object and moving along a predetermined plane; A holding member for holding the optical member; And a first encoder for measuring a distance between a predetermined reference position and the holding member in a first axial direction parallel to the plane.

According to this, the distance in the first axial direction from the reference position to the holding member holding the optical member is measured by the first encoder. This makes it possible to measure the distance from the reference position to the optical member precisely even if there is an atmosphere change such as temperature fluctuation around the first encoder and the holding member. Therefore, the movable body can be accurately moved or positioned with respect to the optical system member.

According to a second aspect of the present invention, there is provided an exposure apparatus for exposing an object with an energy beam through an optical member, comprising: a movable body holding the object and capable of moving in a predetermined plane; A holding member for holding the optical member; And an encoder device for measuring a positional information of the optical member with respect to a direction parallel to the predetermined plane, the scale being provided on one of the optical member and the holding member and the head being provided on the other side .

According to this aspect, the position information of the optical member relating to the direction parallel to the predetermined plane is measured by the encoder device in which the scale is provided on one of the optical member and the holding member and the head is provided on the other side. This makes it possible to accurately measure the positional information of the optical member even when the atmosphere changes such as fluctuation of temperature, for example, around the holding member.

According to a third aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: forming a pattern on an object using any one of the first and second exposure apparatuses of the present invention; And developing the object on which the pattern is formed.

According to a fourth aspect of the present invention, there is provided an exposure method for exposing an object through an optical member with an energy beam and forming a pattern on the object, the method comprising: And a first measuring step of measuring the positional relationship in the moving surface of the moving body by using an encoder system.

According to this aspect, the positional relationship between the optical member and the predetermined reference position in the moving plane of the moving body holding the object is measured using the encoder system. This makes it possible to precisely measure the positional relationship between the optical member and the predetermined reference position within the moving surface of the moving body. Therefore, the movable body can be accurately moved or positioned with respect to the optical system member.

According to a fifth aspect of the present invention, there is provided an exposure method for exposing an object held by a moving object capable of moving in a predetermined plane with an energy beam through an optical member, wherein the optical member and a holding member And measuring the positional information of the optical member with respect to a direction parallel to the predetermined plane by using an encoder device provided with a scale on one side and a head on the other side.

According to this, the position information of the optical member with respect to the direction parallel to the predetermined plane is measured by using the encoder device in which the scale is provided on one of the optical member and the holding member and the head is provided on the other side. This makes it possible to accurately measure the positional information of the optical member even when the atmosphere changes such as fluctuation of temperature, for example, around the holding member.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: forming a pattern on an object using any one of the first and second exposure methods of the present invention; And developing the object on which the pattern is formed.

1 is a schematic view showing an exposure apparatus according to an embodiment.

2 (A) is a view for explaining the arrangement of a head unit and a pickup, and FIG. 2 (B) is a plan view showing a wafer stage.

3 is a perspective view showing the measurement mount.

Fig. 4 is a view for explaining the arrangement of scales provided on the pickup and the barrel.

5 is a block diagram showing the control system of one embodiment.

Hereinafter, one embodiment of the present invention will be described with reference to Figs. 1 to 5. Fig.

Fig. 1 shows a schematic configuration of an exposure apparatus 10 according to an embodiment. This exposure apparatus 10 is a step-and-scan type projection exposure apparatus, that is, a so-called scanning stepper. As will be described later, in this embodiment, a projection optical system PL is provided. Hereinafter, the optical axis direction of the projection optical system PL is referred to as a Z-axis direction, a direction in which the reticle and the wafer are relatively scanned Axis direction, the direction orthogonal to the Z-axis and the Y-axis is referred to as the X-axis direction, and the rotation (inclination) directions around the X-axis, Y-axis, and Z- do.

The exposure apparatus 10 includes an illumination unit IOP, a reticle stage RST for holding the reticle R, a projection unit PU including a projection optical system PL, A wafer stage WST moving in a plane, a control system thereof, and a column 34 for holding the projection unit PU.

The illumination unit IOP includes a light source and an illumination optical system and illuminates the illumination light IL in a rectangular or arcuate illumination area defined by a visual field stop (also referred to as a masking blade or a reticle blind) disposed therein, The reticle R having the pattern formed thereon is illuminated with a uniform illumination. As an example of the illumination light IL, an ArF excimer laser light (wavelength: 193 nm) is used as an example.

The reticle stage RST is disposed on a reticle stage base 32a constituting an upper plate of a column 34 to be described later and is formed of a magnetic field generated by a magnetic levitation type two dimensional linear actuator constituting the reticle stage driving system 19R And supported on the reticle stage base 32a by the lifting force. On the reticle stage RST, the reticle R is fixed, for example, by vacuum adsorption or electrostatic adsorption.

The reticle stage RST is driven by the reticle stage driving system 19R in a predetermined stroke in the Y-axis direction (left-right direction in FIG. 1), and is moved in the X-axis direction Direction, and also in the Z-axis direction and in the oblique directions (? X and? Y directions) with respect to the XY plane.

The position (including the rotation in the? Z direction) of the reticle stage RST (reticle R) in the XY plane is determined by a reticle laser interferometer (hereinafter referred to as " reticle stage " (Referred to as a " reticle interferometer ") 18R, for example, is always detected with a resolution of about 0.25 nm to 1 nm. The position of the reticle R in the Z axis direction is measured by a reticle focus sensor RF (not shown in Fig. 1, see Fig. 5), which is a multi-point focal point position detecting system disclosed in, for example, U.S. Patent No. 5,448,332 do.

The measured values of the reticle interferometer 18R and the reticle focus sensor RF are supplied to the main controller 11 (see Fig. 5). The main control apparatus 11 drives the reticle stage RST through the reticle stage driving system 19R based on the supplied measurement value.

The projection unit PU has a cylindrical barrel 40 and a projection optical system PL composed of a plurality of optical elements held in the barrel 40. [ In the present embodiment, the lens barrel 40 is a single lens barrel. However, for example, a plurality of lens barrels holding one or a plurality of optical elements may be superimposed. In this case, it is preferable that the plurality of barrels are accommodated in the sealing member to maintain the cleanliness of the projection optical system PL at a high level.

As the projection optical system PL, for example, a refractive optical system comprising a plurality of optical elements (lens elements) arranged along an optical axis parallel to the Z-axis direction is used. The projection optical system PL has a projection magnification (for example, 1/4 or 1/5) predetermined by bilateral telecentricity. Therefore, when the above-described illumination area is illuminated by the illumination light IL from the illumination unit IOP, the reticle R, which is disposed so that the first surface (object surface) of the projection optical system PL is substantially coincident with the pattern surface, (A part of the projected image of the circuit pattern) of the circuit pattern of the reticle R in the illumination area through the projection optical system PL is projected onto the second surface (projection surface) of the projection optical system PL by the illumination light IL passing through the projection optical system PL, (Exposure area) on the surface of the wafer W coated with a resist (photosensitive agent) on the surface thereof.

The reticle R is relatively moved in the scanning direction (Y-axis direction) with respect to the illumination region (illumination light IL) by the synchronous driving of the reticle stage RST and the wafer stage WST, One shot area (partition area) on the wafer W is scan-exposed by relatively moving the wafer W in the scanning direction (Y-axis direction) with respect to the shot area The pattern of the reticle R is transferred. That is, in the present embodiment, a pattern is formed on the wafer W by the illumination unit IOP, the reticle R, and the projection optical system PL, and the exposure is performed on the wafer W by the illumination light IL, Layer is formed on the wafer W by exposure.

The column 34 has a plurality of (here, for example, three) leg portions 32b (leg portions inside the sheet are not shown) to which the lower ends thereof are fixed on the upper surface (floor surface) And a reticle stage base 32a supported above the upper surface F by a reticle stage base 32a. At the center of the reticle stage base 32a, a rectangular opening 34a is formed when viewed in a plane passing through in the vertical direction (Z-axis direction) (as viewed from above).

The lens barrel 40 is, for example, a cylindrical hollow member having a longitudinal direction in which the projection optical system PL is accommodated in the Z axis direction, and a projection is formed at the center of the bottom wall. An optical member positioned at the lower end of the projection optical system PL is held inside the projection, and an opening portion serving as a passage for the illumination light is formed at the center of the projection. The bottom wall of the lens barrel 40 is constituted by a plate member having a circular opening at its center and a holding member for holding the optical member positioned at the lower end of the projection optical system PL from the circular opening is projected .

A ring-shaped flange (FLG) is integrally provided at the outer peripheral portion of the lens barrel (40) at a position slightly below the center in the height direction.

The lens barrel 40 is attached to the flange FLG by a plurality of, for example, three suspension supporting mechanisms 137 (one of which is not shown on the inner side of the drawing) fixed to the lower surface of the reticle stage base 32a. So that it is suspended at the lower side of the reticle stage base 32a. Each of the suspension supporting mechanisms 137 includes a coil spring 136 and a wire 135, which are, for example, connecting members of oil-structure. The coil spring 136 vibrates like a pendulum in a direction perpendicular to the optical axis (Z axis) of the projection optical system PL to suppress vibration in a direction perpendicular to the optical axis of the projection optical system PL ) Is prevented from being transmitted to the projection optical system PL]. The coil spring 136 also has a high vibration damping performance in the direction parallel to the optical axis. When the lens barrel supporting the projection unit PU is provided, the lens barrel base may be suspended by three suspension supporting mechanisms 137, for example.

A convex portion 134a is formed in the vicinity of the central portion of each of the three leg portions 32b of the column 34 with respect to the Z-axis direction. A drive mechanism 440 is provided between each convex portion 134a and the flange FLG of the projection optical system PL. Each driving mechanism 440 includes a voice coil motor for driving the projection optical system PL in the radial direction of the lens barrel 40 and a voice coil motor for driving the projection optical system PL in the optical axis direction have. The projection optical system PL is moved in the 6-degree-of-freedom direction (not shown) by the three drive mechanisms 440 (the drive mechanism inside the paper in Fig. 1) provided between each of the three convex portions 134a and the flange FLG Respectively. In this embodiment, the main controller 11 (see Fig. 5) is provided with a projection optical system PL (projection optical system PL), based on the acceleration information detected by an acceleration sensor (not shown) provided on the flange FLG of the projection optical system PL The driving of the voice coil motor of each driving mechanism 440 is controlled so as to be stationary with respect to the column 34 and the upper surface F. [

The wafer stage WST is disposed below the projection optical system PL and is mounted on a stage base BS provided horizontally on the upper surface F through a plurality of non-contact bearings, for example, air bearings, . The wafer W is held on the wafer stage WST by vacuum adsorption (or electrostatic adsorption) through a wafer holder (not shown).

The position of the wafer stage WST is measured by an encoder system disclosed in, for example, U.S. Patent Application Publication No. 2007/0288121, U.S. Patent Application Publication No. 2008/0088843, U.S. Patent Application Publication No. 2006/0227309, do. In this embodiment, the encoder system has four linear encoders 70A to 70D (see Fig. 5), and as shown in Fig. 2A, four encoder head units 62A to 62D (Holding member) 51 (described later in detail). On the other hand, as shown in FIG. 2 (B), on the upper surface of the wafer stage WST, a pair of Y scales 44A, 44C, and a pair of X scales 44B, 44D, respectively. On the surface of each of the scales 44A to 44D, there is formed a reflection type diffraction grating whose longitudinal direction is the periodic direction.

The surface (upper surface) on the + Z side of the stage table BS is processed to have a very high flatness and serves as a reference surface (guide surface) at the time of moving the wafer stage WST. The wafer stage WST is driven by the wafer stage driving system 19W in a predetermined stroke in the Y-axis direction, is microdriven in the X-axis direction and the? Z direction, and is also driven in the Z-axis direction and the oblique direction? X Direction and the &thetas; y direction).

The flange FLG of the projection optical system PL is suspendedly supported by a plurality of (four, for example, four) support members 53 (however, a support member on the inside of the sheet is not shown). Each of the support members 53 actually comprises a link member having flexure portions at both ends thereof. Each flexure portion has a high stiffness with respect to the longitudinal direction (Z-axis direction) of the support member, and the stiffness with respect to the other five degrees of freedom direction is low. Therefore, the measurement mount 51 is supported by almost no stress between the measurement mount 51 and the flange FLG by the four support members.

As shown in the perspective view of Fig. 3, the measurement mount 51 includes a circular plate-like main body portion 52 and a plurality of measurement mounts 51 arranged in the + X direction, + Y direction, -X direction, and -Y direction from the main body portion 52 And has four extending portions 53A, 53B, 53C, and 53D having a substantially square shape when viewed from the plane where the projections are installed.

The main body portion 52 has a concave portion 52a whose inner bottom surface is lower than the rim portion except for the ring-shaped rim portion on the outer peripheral edge of the upper surface. An annular surface region parallel to the upper surface slightly lower than the inner bottom surface of the concave portion 52a is formed at the center of the concave portion 52a. The inner circumferential edge and the outer circumferential edge of the annular surface region are at the same center as the aforementioned rim portion. The inner peripheral edge of the face region is an inner peripheral face of the circular opening 52c. The surface region and the inner bottom surface of the concave portion 52a are connected by a tapered inclined surface. The accommodating portion 52b is formed by a surface area around the circular opening 52c and a tapered inclined surface.

As shown in Fig. 2A and Fig. 3, on the inner bottom surface of the concave portion 52a of the measurement mount 51, there are provided sensor heads 50a and 50y (see Fig. 5) A pickup 54x, and a pickup 54y.

The pick-up 54x is provided on the straight line Px as shown in Fig. 2A and has an x head 56x for irradiating light in the upward direction (+ Z direction). Likewise, the pickup 54y is disposed on the straight line Py, and has a y head 56y for radiating light upward.

On the lower surface of the projection unit PU (the surface on the -Z side), for example, on the lower surface of the lens barrel 40, x-scale 58x is shown on the lower surface of the lens barrel 40 as opposed to each of the pickups 54x and 54y The x-scale 58x and the y-scale 58y are fixed.

The x-scale 58x is arranged on a straight line Px orthogonal to the optical axis of the projection optical system PL and at an angle of 45 degrees with respect to the X-axis and parallel to the straight line Px as shown in the arrangement diagram (A) The y-scale 58y is arranged on the straight line Py which is orthogonal to the optical axis of the projection optical system PL and has an angle of 45 degrees with respect to the Y-axis and which is parallel to the straight line Py, As shown in Fig. A reflection type diffraction grating in which the longitudinal direction is a periodic direction is formed on the lower surface (-Z side surface) of the scales 58x and 58y.

The pickup 54x is arranged on a straight line Px due to, for example, vibration or the like by using reflected light (diffracted light from the diffraction grating) obtained by irradiating light to the x-scale 58x fixed on the lower surface of the lens barrel 40 And constitutes an optical x linear encoder 50x (see Fig. 5) for detecting the displacement of the lens barrel 40 (projection optical system PL) in the parallel direction. Likewise, the pickup 54y is arranged so as to be able to receive the light beam (diffracted light from the diffraction grating) obtained by irradiating the light onto the y-scale 58y fixed to the lower surface of the barrel 40, (See Fig. 5) for detecting the displacement of the projection optical system PL (projection optical system PL).

Here, in the x linear encoder 50x and the y linear encoder 50y, a diffraction interfering type head of the same construction as that of an encoder head disclosed in, for example, U.S. Patent No. 7,238,931 and U.S. Patent Application Publication No. 2007/0288121, (54x, 54y). However, in the present embodiment, the pickups 54x and 54y include a polarization beam splitter that is disposed outside the measurement mount 51 and includes a light source and a photodetector (including a photodetector), and separates the light from the light source Only a part of the optical system is disposed on the inner bottom surface of the concave portion 52a of the measurement mount 51, that is, opposed to the x-scale 58x and the y-scale 58y. That is, all of the pickups 54x and 54y may not be provided on the measurement mount 51. [ In this case, light and / or signals are transmitted / received between the light source, the light receiving system, and the optical system through an optical fiber (not shown) or by air transmission. Hereinafter, the optical system disposed on the inner bottom surface of the concave portion 52a of the measurement mount 51 is called a pickup. Of the pickups 54x and 54y, the members disposed outside the measurement mount 51 are not limited to the light source and the light receiving system, and may be only the light source or only the light source and the light receiving element (sensor), for example.

As shown in FIG. 2A, four encoder head units (also referred to as " encoder head units ") are disposed on the lower surface (-Z side surface) of the measurement mount 51 so as to surround the lower end portion of the projection optical system PL in all directions (Hereinafter also referred to as a head unit) 62A to 62D.

The head units 62A and 62C are arranged symmetrically with respect to the optical axis of the projection optical system PL with the X axis direction being the longitudinal direction on the + X side and the -X side of the projection unit PU, respectively. The head units 62B and 62D are arranged symmetrically with respect to the optical axis of the projection optical system PL with the Y axis direction being the longitudinal direction on the + Y side and -Y side of the projection unit PU.

As shown in Fig. 2A, the head units 62A and 62C are provided with a plurality of Y heads 64 arranged at predetermined intervals along the X-axis direction. The head unit 62A includes a plurality of Y heads 64 for measuring the Y-axis position (Y position) of the wafer stage WST using the Y scale 44A described above on the wafer stage WST (Five-eye) Y linear encoder 70A (refer to FIG. 5) provided therein. Similarly, the head unit 62C includes a 5-Y linear encoder 70C (also referred to as a 5-Y linear encoder) 70C having five Y heads 64 for measuring the Y position of the wafer stage WST, using the Y- 5).

As shown in Fig. 2A, the head units 62B and 62D are provided with a plurality of, here, five X heads 66 arranged at predetermined intervals along the Y-axis direction. The head unit 62B includes a plurality of X heads 66 for measuring a position (X position) in the X axis direction of the wafer stage WST using the X scale 44B described above, X linear encoder 70B (see Fig. 5). Similarly, the head unit 62D includes a 5-axis X linear encoder 70D (also referred to as a 5-axis X linear encoder) 70D having five X heads 66 for measuring the X position of the wafer stage WST, 5).

1, the upper end of the measurement mount 51 is fixed (connected) to the flange FLG, and the lower end of the measurement mount 51 is fixed (connected) to the extending portions 53A to 53D, respectively The four supporting members 53 described above (the support member on the inside of the sheet is not shown) are suspended and supported, and are disposed at a position downward (-Z direction) by a predetermined distance from the lower surface of the barrel 40. 4, the projecting portion at the lower end of the barrel 40 is accommodated in the accommodating portion 52b formed in the measurement mount 51. In this state, 4, the lower surface of the lens barrel 40 and the inner bottom surface of the concave portion 52a face each other through a predetermined gap, and the x head 56x of the pickup 54x and the lens barrel 40 face each other, The y-scale 56y of the pickup 54y faces the y-scale 58y disposed on the lower surface of the barrel 40, and the x-scale 58x disposed on the lower surface of the barrel 44 faces the y-

An alignment system (ALG), a wafer focus sensor WF, and the like (see Fig. 5) are mounted on the measurement mount 51. [ As the alignment system (ALG), a sensor of an image processing system can be used, and a sensor of this image processing system is disclosed in, for example, Japanese Patent Application Laid-Open No. 04-065603 (corresponding US Patent No. 5,493,403). As the wafer focus sensor WF, a wafer focus sensor disclosed in, for example, Japanese Patent Application Laid-Open No. 06-283403 (corresponding US Patent No. 5,448,332) can be used.

In the present embodiment, since the above-described scales 58x and 58y, the head units 62A to 62D, and the like are provided on the measurement mount 51, the measurement mount 51 can also be referred to as a metrology frame or the like . In this embodiment, not only the scales 58x and 58y but also the head units 62A to 62D, the alignment system (ALG), and the wafer focus sensor WF are provided on the measurement mount 51. However, At least one of the head units 62A to 62D, the alignment system (ALG), and the wafer focus sensor (WF) may be provided in a member different from the measurement mount 51.

Fig. 5 is a block diagram of the control system of the exposure apparatus 10 of the present embodiment. The control system shown in Fig. 5 includes a so-called microcomputer (or workstation) composed of a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory) and the like, And is configured mainly around the main controller 11.

In the exposure apparatus 10 configured as described above, when the wafer stage WST holding the wafer W in the exposure operation is positioned below the measurement mount 51, the wafer stage WST disposed on the upper surface of the wafer stage WST The Y scales 44A and 44C and the head units 62A and 62C are opposed to each other and the X scales 44B and 44D and the head units 62B and 62D are opposed to each other. The positions of the wafer stage WST in the Y-axis direction are measured by the head units 62A and 62C (Y linear encoders 70A and 70C) opposed to the Y scales 44A and 44C, The position of the wafer stage WST in the X-axis direction is measured by the head units 62B and 62D (X linear encoders 70B and 70D) opposed to the wafer stage WST. At the same time, a pickup 54x (x linear encoder 50x) opposed to the x-scale 58x disposed on the lower surface of the barrel 40 and a pickup 54y opposed to the y-scale 58y And the position of the lens barrel 40 in the XY plane are measured in a direction parallel to the straight line Px and the straight line Py of the lens barrel 40. [ The main controller 11 monitors the measurement results of the Y linear encoders 70A and 70C and the X linear encoders 70B and 70D and the measurement results of the x linear encoder 50x and the y linear encoder 50y, The wafer stage WST is moved in the XY plane with respect to the lens barrel 40 as a reference.

As described above, according to the exposure apparatus 10 of the present embodiment, the displacement in the XY plane of the barrel 40 during the exposure operation is opposite to the scale 58x disposed on the lower surface of the barrel 40 A pickup 54x (x linear encoder 50x) disposed on the measurement mount 51 and a pickup 54y disposed on the measurement mount 51 opposed to the scale 58y disposed on the lower surface of the barrel 40, [y linear encoder 50y]. Therefore, even if the position of the lens barrel 40 in the XY plane is slightly changed due to vibration or the like caused by the movement of the wafer stage WST or the like, it becomes possible to measure the displacement with high precision, It is possible to precisely control the position of the wafer stage WST with reference to the optical axis of the projection optical system PL.

Light emitted from the pickups 54x and 54y (hereinafter referred to as spot light) is reflected by the x-scale 58x or the y-scale 58y and is fixed to the pickup 54x and 54y and the barrel 40 Scale 58x or the y-scale 58y, but the path length of the incident light is negligibly small as compared with the path of the incident light in the interferometer, for example. Therefore, even if air fluctuation or the like occurs around the lens barrel 40 or the like during exposure, the short-term stability of the measured values of the x linear encoder 50x and the y linear encoder 50y can be remarkably improved as compared with the case of using an interferometer .

In this embodiment, the pick-ups 54x and 54y for emitting the spot light used for the displacement measurement of the lens barrel 40 and the head units 62A to 62D for measuring the position of the wafer stage WST are both mounted on the measurement mount (Not shown). Therefore, the positional relationship between the pick-ups 54x and 54y and the head units 62A to 62D is kept constant, and the X linear encoders 70B and 70D and the Y linear encoder It is possible to reduce a measurement error occurring between the x linear encoder 50x and the y linear encoder 50y which perform the measurement with respect to the lens barrel 70A and 70C.

In the above embodiment, the x linear encoder 50x and the y linear encoder 50y are arranged such that a straight line Px forming an angle of 45 degrees with respect to the X and Y axes and a lens barrel 40 parallel to the straight line Py However, the present invention is not limited to this. The displacement in the X-axis direction and the Y-axis direction of the lens barrel 40 may be measured using an encoder, and the displacement in any two different axial directions may be measured The displacement of the lens barrel 40 on the XY plane may be measured. That is, the scales 58x and 58y are not limited to the directions parallel to the straight lines Px and Py in the longitudinal direction (measurement direction, periodic direction / arrangement direction of the diffraction grating), but may be arbitrary.

In the above embodiment, only the optical system (part of the optical system) is disposed on the measurement mount 51 in order to avoid a heat source (heat source). However, in the case where the thermal influence can be eliminated, A light source and / or a light receiving device (including a light detector) may be disposed on the measurement mount 51. [

Although the pickups 54x and 54y of the x linear encoder 50x and the y linear encoder 50y are attached to the measurement mount 51 in the above embodiment, the pickup 54x and 54y are not limited to this, The displacement of the barrel 40 with respect to the measurement mount 51 may be measured by using the scale 58x and 58y attached to the measurement mount 51 by attaching the barrel 40 to the barrel 40. [

Although the pickups 54x and 54y or the scales 58x and 58y are attached to the lower end surface of the projection unit PU (the barrel 40) so far, the projection unit PU (barrel 40) The pickups 54x and 54y or the scales 58x and 58y may be fixed to portions other than the lower end surface of the pickup 54x and 54y.

In the above embodiment, the optical x linear encoder 50x and the y linear encoder 50y are used for displacement measurement of the lens barrel 40, but the present invention is not limited to this. For example, an electromagnetic induction type encoder may be used .

In the above embodiment, the displacement of the lens barrel 40 is measured by using the x linear encoder 50x and the y linear encoder 50y having the pickups 54x and 54y that receive the reflected light obtained by irradiating the scale with light However, the present invention is not limited to this. As the encoder for measuring the displacement of the lens barrel 40, for example, an encoder for measuring the displacement using the transmitted light transmitted through the scales 58x and 58y can be employed.

Further, the encoder is not limited to any other two-axis directions such as the X axis and the Y axis, and the displacement of the lens barrel 40 may be measured even in the other direction (e.g., the? Z direction).

Further, in the above embodiment, the projection unit PU (projection optical system PL) is suspended by the three suspension supporting mechanisms 137 via the flange FLG and below the reticle stage base 32a However, the present invention is not limited to this, and the projection unit PU (projection optical system PL) may be supported by a lens barrel base horizontally supported on a floor surface through a vibration isolating device. In this case, the measurement mount 51 may be suspended by the barrel base plate. The point is that the positional relationship in the XY plane between the projection unit PU (projection optical system PL) and the reference position can be measured by the linear encoder. At least one of the head units 62A to 62D, the alignment system (ALG), and the wafer focus sensor (WF) may be provided independently of the measurement mount 51 on the barrel base plate.

Although the position measurement of the wafer stage WST is performed by using the encoder system including the X linear encoders 70B and 70D and the Y linear encoders 70A and 70C in the present embodiment, ) Is not limited to this. For example, the position measurement of the wafer stage WST may be performed by an interferometer system or an interferometer system and an encoder system. In this interferometer system, since it is not necessary to measure the position of the wafer stage with reference to the projection optical system PL, the reflecting surface of the measurement beam of the interferometer system need not be provided in the projection optical system PL. Further, an exposure apparatus having both an interferometer system and an encoder system is disclosed in, for example, U.S. Patent Application Publication No. 2007/0288121, U.S. Patent Application Publication No. 2008/0088843, and the like.

In the above embodiment, an encoder system having a structure in which a lattice portion (Y scale, X scale) is provided on a wafer table (wafer stage) and an X head and a Y head are disposed outside the wafer stage However, the present invention is not limited to this. For example, as disclosed in U.S. Patent Application Publication No. 2006/0227309, etc., an encoder head is provided on a wafer stage, and on the outside of the wafer stage, (For example, a two-dimensional lattice or a one-dimensional lattice portion arranged two-dimensionally) may be disposed. In this case, the Z head for measuring the position of the wafer table in the Z-axis direction may also be provided on the wafer stage, and the surface of the lattice portion may be a reflection surface to which the measurement beam of the Z head is irradiated. In this case, a single head having the functions of the encoder head and the Z head may be used. The lattice portion (scale) may be supported by, for example, the above-described measurement mount or barrel support plate.

In the above embodiment, the present invention is applied to the scanning stepper. However, the present invention is not limited to this, and the present invention may be applied to a stationary exposure apparatus such as a stepper. The present invention is also applicable to a step-and-stitch projection exposure apparatus that synthesizes a shot area and a shot area.

The magnification of the projection optical system in the exposure apparatus of the above embodiment may be not only the reduction system but also the equalization and enlargement system. The projection optical system PL may be any of a refractometer, a refractometer and a refractometer, The projected image may be either an in-phase image or an orthographic image.

The illumination light IL is not limited to ArF excimer laser light (wavelength 193 nm) but may be ultraviolet light such as KrF excimer laser light (wavelength 248 nm) or vacuum ultraviolet light such as F ₂ laser light (wavelength 157 nm) . In addition, a bright line of an ultraviolet range such as g-line (wavelength 436 nm) and i-line (wavelength 365 nm) generated from the ultra high pressure mercury lamp may be used as the illumination light IL. In addition, as disclosed in, for example, U.S. Patent No. 7,023,610, vacuum ultraviolet light can be used as the ultraviolet laser light emitted from the DFB semiconductor laser or the fiber laser, or the single wavelength laser light in the visible range, such as erbium (or erbium and ytterbium A harmonic wave which is amplified by a doped fiber amplifier and wavelength-converted into ultraviolet light by using a nonlinear optical crystal may be used.

In the embodiment described above, it is needless to say that the illumination light IL of the exposure apparatus is not limited to light having a wavelength of 100 nm or more, and light having a wavelength of less than 100 nm may be used. For example, in order to expose a pattern of 70 nm or less in recent years, extreme ultraviolet (EUV) light in a soft X-ray region (for example, a wavelength range of 5 nm to 15 nm) is generated using a SOR or a plasma laser as a light source, (E.g., 13.5 nm), and an EUV exposure apparatus using a reflective mask are being developed. In this apparatus, since a configuration in which scanning exposure is performed by synchronously scanning a mask and a wafer using arc illumination is considered, the present invention can be applied to such a device. In addition, the present invention can be applied to an exposure apparatus using charged particle beams such as electron beams or ion beams.

The present invention can also be applied to, for example, an immersion exposure apparatus disclosed in International Publication WO99 / 49504 pamphlet and the like, in which a liquid (e.g., pure water) is filled between a projection optical system PL and a wafer.

In the above embodiment, a light-transmitting mask (reticle) in which a light-shielding pattern (or a phase pattern and a light-shielding pattern) predetermined in advance is formed on a light-transmissive substrate is used. Instead of this reticle, for example, US Pat. No. 6,778,257 As described above, an electronic mask (variable mold mask) for forming a transmission pattern, a reflection pattern, or a light emission pattern may be used based on electronic data of a pattern to be exposed.

Furthermore, an exposure apparatus (lithography system) for forming a line-and-space pattern on a wafer W by forming an interference fringe on the wafer W as disclosed in, for example, International Publication No. 2001/035168 pamphlet, Can be applied.

Further, as disclosed in, for example, U.S. Patent No. 6,611,316, two reticle patterns are synthesized on a wafer through a projection optical system, and exposure is performed in which one shot region on the wafer is almost double- The present invention can be applied to an apparatus.

In addition, in the above embodiment, the object (the object to be exposed to which the energy beam is irradiated) to be patterned is not limited to the wafer but may be another object such as a glass plate, a ceramic substrate, a film member, or a mask blank.

The use of the exposure apparatus is not limited to the exposure apparatus for semiconductor manufacturing. For example, it is possible to use a liquid crystal exposure apparatus for transferring a liquid crystal display element pattern onto an angled glass plate, an organic EL, a thin film magnetic head, , A micromachine, a DNA chip, and the like. In addition, in order to manufacture a reticle or mask used in a photolithography apparatus, EUV exposure apparatus, X-ray exposure apparatus, and electron beam exposure apparatus as well as microdevices such as semiconductor elements, a circuit pattern is transferred onto a glass substrate or a silicon wafer The present invention can also be applied to an exposure apparatus.

Further, all publications relating to the exposure apparatus and the like cited in the foregoing description, the international publication pamphlet, the disclosure of the U.S. patent application publication and the U.S. patent specification are referred to as a part of the description of this specification.

In addition, the semiconductor device can be manufactured by performing the function / performance design of the device, fabricating the reticle based on the designing step, fabricating the wafer with the silicon material, and exposure apparatus (pattern forming apparatus) A lithography step of transferring the pattern of the mask (reticle) onto the wafer, a developing step of developing the exposed wafer, an etching step of removing the exposed member of the part other than the part where the resist remains, by etching, Removing the resist, removing the device (including a dicing process, a bonding process, and a packaging process), an inspection step, and the like. In this case, since the exposure apparatus of the above embodiment is used in the lithography step, a highly integrated device can be manufactured with good yield.

INDUSTRIAL APPLICABILITY As described above, the exposure apparatus, the exposure method, and the device manufacturing method of the present invention are suitable for manufacturing electronic devices such as semiconductor devices and liquid crystal display devices.

Claims (22)

An exposure apparatus for exposing an object with an energy beam through an optical member, A moving body for holding the object, A first scaffold disposed on one of the moving body and the intermediate member so as to be parallel to a predetermined plane orthogonal to an optical axis of the optical member; and a second scaffold provided on the other of the moving body and the intermediate member, A first encoder system for measuring a first positional relationship between the moving body and the intermediate member in the plane based on the output of the at least one first head, A second scraper portion provided on a lower surface of the lens barrel holding the optical member, the second scraper portion being parallel to the plane and not exposed to the outside of the lens barrel, and a second scraper portion, And a second encoder system for measuring a second positional relationship between the optical member and the intermediate member in the plane based on the output of the at least one second head, Wherein the moving body is driven based on the first positional relationship measured and the second positional relationship measured. 2. The apparatus according to claim 1, wherein the first encoder system measures the first positional relationship with respect to two directions intersecting with each other in the plane, And the second encoder system measures the second positional relationship with respect to two directions intersecting with each other in the plane. 3. The apparatus according to claim 2, wherein the first encoder system measures the first positional relationship with respect to the first direction and the second direction intersecting with each other in the plane, And the second encoder system measures the second positional relationship with respect to the third direction and the fourth direction which intersect with each other in the plane. The exposure apparatus according to claim 3, wherein the first direction and the second direction are orthogonal to each other, and the third direction and the fourth direction are orthogonal to each other. 5. The exposure apparatus according to claim 4, wherein the first direction and the third direction intersect each other at 45 degrees. The exposure apparatus according to claim 1, wherein the first scale section has a two-dimensional grating. 2. The apparatus according to claim 1, wherein the first scale section is disposed in the moving body, Wherein the at least one first head is provided in the intermediate member. An exposure apparatus for exposing an object with an energy beam through an optical member, A moving body for holding the object, A first scaffold disposed on one of the moving body and the intermediate member so as to be parallel to a predetermined plane orthogonal to an optical axis of the optical member; and a second scaffold provided on the other of the moving body and the intermediate member, A first encoder system for measuring a first positional relationship between the moving body and the intermediate member in the plane based on the output of the at least one first head, A plurality of scales parallel to the plane provided on the lower surface of the barrel holding the optical member and at least two second heads irradiating the measurement beams to the plurality of scales respectively and provided in the intermediate member, A second encoder system for measuring a second positional relationship between the optical member and the intermediate member in the plane based on the output of at least two second heads, Wherein the moving body is driven based on the first positional relationship measured and the second positional relationship measured. The exposure apparatus according to claim 8, wherein the second encoder system measures, as the second positional relationship, a positional relationship between two mutually intersecting directions and a rotational direction in a plane parallel to the plane. The apparatus according to claim 9, wherein the second encoder system is provided with two scales having different measurement directions on the lower surface of the barrel, and on the basis of outputs of the at least two second heads, And the second positional relationship between the optical member and the intermediate member with respect to the first direction and the second direction is measured. delete An exposure method for exposing an object with an energy beam through an optical member, A measurement beam is irradiated onto a first scale portion arranged on one of a moving body holding the object and an intermediate member so as to be parallel to a predetermined plane orthogonal to the optical axis of the optical member, A step of measuring a first positional relationship between the moving body and the intermediate member in the plane using at least one first encoder head provided, And a second scraper portion provided on a lower surface of the barrel holding the optical member, the second scraper portion being parallel to the plane and not exposed to the outside of the barrel, and irradiating the measuring beam with at least one Measuring a second positional relationship between the optical member and the intermediate member in the plane using a second encoder head; A step of driving the moving body on the basis of the measured first positional relationship and the second positional relationship Lt; / RTI > 13. The exposure method according to claim 12, wherein the first and second positional relationships are respectively measured with respect to two directions intersecting with each other in the plane. 14. The method according to claim 13, wherein the first positional relationship is measured in a first direction and a second direction intersecting with each other in the plane, Wherein the second positional relationship is measured with respect to a third direction and a fourth direction intersecting with each other in the plane. 15. The exposure method according to claim 14, wherein the first direction and the second direction are orthogonal to each other, and the third direction and the fourth direction are orthogonal to each other. 16. The method according to claim 15, wherein the first direction and the third direction intersect each other at 45 degrees. 13. The exposure method according to claim 12, wherein the first scale portion has a two-dimensional grating. 13. The apparatus according to claim 12, wherein the first scale portion is disposed in the moving body, Wherein the at least one first head is provided in the intermediate member. An exposure method for exposing an object with an energy beam through an optical member, A measurement beam is irradiated onto a first scale portion arranged on one of a moving body holding the object and an intermediate member so as to be parallel to a predetermined plane orthogonal to the optical axis of the optical member, Measuring a first positional relationship between the moving body and the intermediate member in the plane based on an output of the at least one first encoder head provided; Wherein the measuring beam is irradiated to each of a plurality of scales parallel to the plane and provided on the lower surface of the barrel holding the optical member, and based on the output of at least two second encoder heads provided in the intermediate member, Measuring a second positional relationship between the optical member and the intermediate member in the first position, A step of driving the moving body on the basis of the measured first positional relationship and the second positional relationship Lt; / RTI > The exposure method according to claim 19, wherein the second positional relationship is measured with respect to two directions and a rotational direction intersecting each other within a plane parallel to the plane. The apparatus according to claim 19, wherein the plurality of scales provided on the lower surface of the barrel include two scales whose measurement directions are different from each other, Wherein the second positional relationship is measured with respect to a first direction and a second direction orthogonal to each other in the plane based on the output of the at least two second heads. A method for manufacturing a semiconductor device, comprising the steps of exposing an object using the exposure method according to any one of claims 12 to 21, A step of developing the exposed object ≪ / RTI >

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